Assessing a method and reference material for quantification of vitamin D binding protein during pregnancy

Area of Science:

• Reproductive biology
• Clinical chemistry
• Biomarker analysis

Background:

• Vitamin D is crucial for maternal and fetal health during pregnancy.
• Accurate measurement of 25-hydroxyvitamin D [25(OH)D] is hindered by increased vitamin D binding protein (VDBP) in maternal serum.
• Current immunoassay methods for VDBP lack standardization and accuracy, complicating clinical comparisons and research.

Purpose of the Study:

• To develop and validate a precise method for quantifying VDBP in human prenatal serum.
• To establish reference values for VDBP concentrations across pregnancy trimesters.
• To support accurate vitamin D status assessment in pregnant women.

Main Methods:

• Development of a liquid chromatography-isotope dilution mass spectrometry (LC-IDMS) method for VDBP quantification.
• Utilized isotopically labeled peptides as internal standards for enhanced accuracy.
• Quantified VDBP in Standard Reference Material® (SRM) 1949 Frozen Human Prenatal Serum.

Main Results:

• VDBP concentrations were lowest in non-pregnant women's serum.
• A progressive increase in VDBP levels was observed across each trimester of pregnancy.
• The LC-IDMS method demonstrated good repeatability and suitability for reference value assignment.

Conclusions:

• The developed LC-IDMS method provides accurate VDBP quantification during pregnancy.
• Understanding VDBP concentration changes is vital for interpreting vitamin D status in pregnant individuals.
• Accurate VDBP measurement can aid in monitoring pregnancy outcomes and ensuring optimal maternal-fetal health.